×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

valve or flange in "operational" 20" 70 bar steam pipe

valve or flange in "operational" 20" 70 bar steam pipe

valve or flange in "operational" 20" 70 bar steam pipe

(OP)
Dear Engineers,

I have a question, which is kind of a long shot, but I still want to ask it;

We have a 200 meter long 20" pipe which is fed at our factory its side with 75bar steam.
At the other side it will be double blocked.
These is no way to block the pipe at our side of the pipe for the next 3 years, and a plant stop is not really an option.

I way wondering or any of you have ever heard of a way to make a block in the pipe at our side, while the pipe is in operation?
It will not really be hot tapping, but maybe there is something comparable?

As a "visualisation", the situation is displayed below smile


I = block
--- = pipe
<- = 75 bar "flow" direction
customer I------------------------------<-- our factory


Thanks

RE: valve or flange in "operational" 20" 70 bar steam pipe

Contact a reputable Hot Tap contractor and ask about "Stopple"
You should also look it up on the web and read about it so you can talk to the Contractor.
Look here:
https://www.google.com/search?q=stopple&tbm=is...

prognosis: Lead or Lag

RE: valve or flange in "operational" 20" 70 bar steam pipe

Maarten-

As pennpiper said, use a line stop device such as a stopple. Depending on how reliable you need for the containment to be, consider installing the stopple, then cutting the pipe a few meters away and installing a flange with a blind. You could use an end cap but you mention three years which to me implies you may want to return this line to service sometime. In that case, pay a bit more for steel and use the flange, as it will make the return to service easier. When you do put it back into service, install a valve first - stopples are ok for one-time stops, but not reliable for multiple uses since the cut edge that the device seals on will not be a clean cut (i.e. it will have corroded a bit) the next time you try to seal against it.

jt

RE: valve or flange in "operational" 20" 70 bar steam pipe

(OP)
Dear Pennpiper and jt,

The option for a Stopple sounds very usefull indeed. Thank you for the suggestion.
I have not found a case online jet where it is used in a 80 bar 480 C (653 K) running steam pipe, but a further contact with some of the suppliers of the system should give more information about that.

Maarten

RE: valve or flange in "operational" 20" 70 bar steam pipe

There are also a number of expandable plugs which might be possible if you can get access to your pipe from downstream of the double block. ?Insert it in there, push with high pressure gas (Nitrogen?) to the point you want to deploy it then activate the sealing plugs either by wire or radio. They are used subsea quite a bit, but depends on how hard is it for you to get access or add a hot tap flange

As with a stopple, it's really a temporary thing to allow you to fit a valve or removable blind, but doesn't require a permanent fitting on the pipe like a stopple.

Also there are newer plug type systems such as http://www.petersenproducts.com/hot_tap_systems.as...

which only require a smaller flange connection. You need to talk to some vendors to see if they do your pressure and temperature.

good luck

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources